1. Field of the Invention
The present invention relates to direct expansion refrigeration apparatus and methods, and in particular, to apparatus and methods employing a condenser, evaporator and heat exchanging equipment.
2. Description of Related Art
The conventional, direct expansion refrigeration system employs an evaporator, compressor, condenser and expansion valve. The compressor compresses and thereby heats a gaseous refrigerant, which is thereafter condensed to release its heat in a condenser cooled by a fan. The liquefied refrigerant then passes through an expansion valve and an evaporator, which evaporate the refrigerant before it is returned to the compressor.
The expansion valve may be a thermal expansion valve that controls the flow rate of refrigerant through the evaporator based on its outlet temperature and pressure. The valve will regulate the evaporator's flow rate to maintain a desirable superheat that allows the refrigerant to evaporate at an appropriate rate. Inadequate evaporation may result in liquid refrigerant entering and damaging the compressor. An excessive evaporation rate may present a high load that can overheat and damage the compressor. Also, excessive evaporation may cause flashing, resulting in pressure fluctuations and premature expulsion of liquid refrigerant from the evaporator.
On a hot day an outdoor condenser may be unable to efficiently discharge heat and may experience an excessively high temperature and pressure. This condition will reduce the system's overall efficiency and may overheat or even damage the compressor. On the other hand, on cooler days the temperature and pressure of the refrigerant may drop, causing moisture to condense and freeze on the outside of an evaporator.
Cooling the average air conditioned home takes more than 2,000 kilowatt-hours per year. This process will also emit into the atmosphere 3,500 pounds of carbon dioxide and 31 pounds of sulfur dioxide per home (commonly designated as the carbon footprint). Today's best air conditioners are 30%-50% more efficient than air conditioners from the 1970's. However there has not been an upgrade in efficiency in nearly a decade, up until the present invention.
Central air conditioners are rated according to Seasonal Energy Efficiency Ratio (SEER). SEER indicates the ratio of the cooling output for a season relative to the amount of energy needed to provide that cooling output. As of January 2006 the minimum SEER allowed on the domestic market is 13 SEER, and the maximum available in standard air conditioning is around 20 SEER.
The presently disclosed apparatus provides an internal hydrothermal cooling loop that will dramatically improve the current Seasonal Energy Efficiency Ratio (SEER), and greatly reduce the carbon footprint left by every air conditioned home.
See also U.S. Pat. Nos. 2,307,380; 2,385,667; 2,791,891; 2,797,554; 3,131,553; 3,824,804; and 4,577,468.